The present disclosure relates to a centrifuge, or a separator, with a vertical axis of rotation. The centrifuge includes a rotatable centrifugal drum and a drive spindle to drive the centrifugal drum. The drive spindle is rotatably mounted via a bearing in a housing supported elastically on a machine framework. Further included is a drive device including a drive motor to rotate the drive spindle and a lubricant system to lubricate the bearing. The lubricant system is configured to deliver lubricant from a lubricant supply tank through a lubricant channel into a region of the bearing.
Such centrifuges, in particular separators, which are suitable in particular for industrial use in continuous operation, are known from the prior art. The known systems include designs in which the drum, the drive spindle and the electric drive motor are connected rigidly to form a structural unit which then, as a whole, is supported elastically on a machine framework. Examples of such prior art are disclosed in FR 1,287,551, DE-B 1 057 979 and DE 43 14 440 C1.
Additional technical background is provided by DE 44 08 182, which discloses a belt drive for a separator, and EP 0 756 897 and WO 98/57752.
DE 2005 001 539 U1 discloses a separator which has a drive belt and also has a circuit-like lubrication system, which is intended for lubricating the spindle-bearing means. The separator has a tubular, scraper-like device which is intended for pumping out lubricant. Such lubricant, which exits out of the bearing means of the drive spindle of the separator drive, can be pumped, via a reprocessing unit, into a lubricant sump, in which the drive spindle, designed as a hollow spindle, is immersed by way of its lower end. This arrangement, however, is still relatively long in the axial direction.
WO 2007/125066 A1 discloses a separator with a direct drive. The direct drive device has an electric drive motor with a stator and a motor rotor, which is aligned with the drive spindle, wherein the stator is connected rigidly to the machine framework and the motor rotor, the drive spindle, the centrifugal drum and the housing form a unit which is supported elastically on the machine framework and oscillates during operation. The bearing device here is arranged between the motor and the drum. The lubrication means of the bearing devices can be accommodated above a partition wall above the drive motor.
Against this background, the present disclosure relates to a further improvement of the construction and the arrangement of the lubrication system of centrifuges, in particular separators with a vertical axis of rotation.
The present disclosure thus relates to a centrifuge that includes a rotatable centrifugal drum and a drive spindle to drive the centrifugal drum. The drive spindle is rotatably mounted via a bearing in a housing supported elastically on a machine framework. Further included is a drive device including a drive motor to rotate the drive spindle and a lubricant system to lubricate the bearing. The lubricant system is configured to deliver lubricant from a lubricant supply tank through a lubricant channel into a region of the bearing. Also included is an injection device, arranged downstream of the lubricant-supply tank, and configured to deliver the lubricant into the region of the bearing by dispensing quantities of lubricant in temporally discrete pulses with a limited-time air stream.
Accordingly, at least one injection device, which is arranged downstream of the lubricant-supply tank, is provided for the purpose of delivering the lubricant. This device is designed for dispensing quantities, for example, small quantities of lubricant in temporally discrete pulses, with a limited-time air stream, into the region of the bearing. This makes it possible for the lubricant requirement to be vastly reduced, for example, when the pulse of oil is blown as a mist into the region of the bearing.
The injection device may be designed as an injection lubricator. Such injection lubricators may have a piston. According to an embodiment of the present disclosure, small quantities of lubricant are thereby dispensed in the separator, at intervals, into the bearing region, for example, at less than 100 mm3 per pulse.
The use of injection lubricators in the field of lubricating a bearing for a centrifuge has not been considered up until now. However, contrary to original expectation, it has been found that it is possible, using such an injection lubricator, for even a separator intended for industrial use to be lubricated adequately with only a very small amount of lubricant without continuous operation being adversely affected.
Using an injection lubricator thus makes it possible for the consumption of lubricant to be reduced to an extremely small quantity, for example, to less than 30 liters per year of operation occurring, for example, over 8000 hours.
It is within the scope of the present disclosure for the injection lubricator to be designed to dispense a quantity of lubricant by a micropump for up to two seconds long, for example, such that, between the individual pulses, there is a pause of more than 60 seconds, and that each pulse is up to two seconds long, for example, one second long.
The injection lubricator may be advantageously designed in order to dispense a quantity of lubricant by a piston for up to two seconds long per pulse, wherein the injection lubricator, furthermore, may be set such that, between the individual pulses, there is a pause of more than 60 seconds, for example, 60 seconds to 180 seconds.
According to the present disclosure, the injection lubricator, may advantageously be designed in order to dispense a quantity of lubricant of between 5 mm3 and 100 mm3, for example, between 10 mm3 and 40 mm3, by a piston, for example, every 60 seconds to 180 seconds.
A lubricant supply which uses up only a particularly small amount of lubricant is realized with only a small number of components. The design, according to the present disclosure, is suitable both for driving via a belt drive and for various types of direct drive with a drive motor arranged in axial extension of the drive spindle or on the drive spindle. These arrangements also make it possible, according to the present disclosure, to realize a construction for the drive device which is short in the vertical direction.
It should be noted that the centrifuge, according to the present disclosure, may also be designed as a solid-bowl centrifuge.
If the centrifuge is designed as a solid-bowl centrifuge, which may have bearings, for example, on either side of a rotatable drum, and, for example, at least one such bearing, each mounted in a ring-like housing, it may be advantageous, according to the present disclosure, if lubricant can be delivered, by at least one injection device, out of the lubricant-supply tank into the region of one or both of the bearings.
Also provided, according to the present disclosure, is a method for directing lubricant into the region of at least one bearing of a centrifuge, according to the present disclosure, in an advantageous and lubricant-saving manner. A respective oil/air mixture is injected in pulses, by at least one injection lubricator, into the region of the at least one bearing.
Additional disclosure, according to the present disclosure, is provided in the claims.
Since the spindle may not used for the lubricant circuit, the spindle can be used for other tasks such as product feeding, for example, through a hollow spindle, according to the present disclosure.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.